Balanced slide-valve



(No Model.)

l G. 000K. BALANGED SLIDE VALVE. No. 527,141. v

O Patented Oct. .9, 1894:.v G? f .C

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"NITED STATES PATENTl OFFICE. i.'

GEORGE COOK, OF BUFFALO, NEV YORK.A

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent N o. 527,141, dated October 9, i894. i

` Applicata ned April/ 26, 1894. sain No. 509.125. oro modem To @ZZ whom it may concern.- Be it known that I, GEORGE COOK, a citizen of the United States, residing at Buffalo, in

the county of Erie and State of New. York;

have invented certain new and usefulImprovements .in Balanced Slide-Valves for Steam-Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable present invention are, first, to so construct the valve as to admit live steam to the lower side thereof .and thereby balance the valve to cause. it to move freely; secondly, to so construct the steam passages in the cylinder and the valve as to diminish the length of the passages and reduce to a minimum the area of the passages in which the steam passes; thirdly, to provide wear plates between the chest and valve which can be renewed vwhenever they are worn at asmall cost; fourthly, to simplify the construction of the exhaust devices with a view to enabling the engineer or machinist to ascertain when the valve and pistons are properly fitted to their seats; and finally, to improve the parts in the details of constructionv so as to promote the efciency and durability of the chest and valve and to savel the expense of refacing the valve and seat.

With these ends in view, the invention consists in the construction and combination of parts which will be hereinafter fully described and claimed.

In the accompanying drawings, Figure l is a longitudinal sectional view partly in eleva tion. Fig. 2 is an enlarged vertical sectional View through a portion of one end of the cylinder and the valve. Fig. 3 is an end view showing the plate by which the valve and exhaust tubes may be adj usted to compensate for wear. Fig. et is a detail view showing the wear plates on the valve. Fig. 5 isa detail View of the wear plates inside the valve chest which form the seats for the sliding valve.

Like letters of reference denote like parts in all the figures, referring to which- -A A denotes the cylinder; B,the piston therein; C, the valve chest, and D the valve. vIn the Wall of the piston cylinder adjacent tothe valve chest are the steam passages E, F, which have their ports e, f, near the ends of the cylinder A- as usual, but in order to diminish the area of steam surface of these passages they are not made as long as the passages shown in my former patent. Hence the other ports e', ffare separated some distance from each other vwhere they open into the valve chest O, as seen in Fig. l. The valve D is cast in a single -piece of metal to form the internal exhaust chamber D and the recess or space d in the lower undersurface ofthe same, said valve being provided at its ends with the feet f, f, in which are provided the exhaust ports g, g,wh.ich open into or communicate with the exhaust chamber D. The feet f, f, of the valve are facedy with the wear plates h h, through which Vare formed the slots h,see Fig. 4, that are in line with the respective exhaust ports g, g; and said slotted wear plates, h, h, are brazed or otherwise suitably united to the valve sothatnthey can be removed when worn and replaced by other wear plates, thus saving the costof refacing the valve by the expensive methods and machinery now used. The seat .for the valve is provided in I the steam chestbythe plates H, H', which are suitably united to the valve and slotted at h (see Fig. 5) to align with the ports e',

f' of the steam passages E, F, in the cylinder;

and in practice I prefer to make the plates h, h, on the valve of brass while the plates H, H', forming the` valve seat may be made of cast iron or steel, but itis evident that these particular'materialscan be changed. By having the recess d in the lower side of the slide valve, which recess extends to and through the sides of the valve, the live steam in the chest, which is supplied by the pipe I, is permitted to pass beneath the valve and thus the steam pressure ou top and bottom of the valve is equal, whereby the valve is balanced and made to work freely and easily in the valve chest. The usual top plate d may be provided on the top side of the valve, or it may be omitted, as desired.

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To the endsof thesteam chest I- apply the adjustable plates J, J', which are" provided with the vertical slots j, see Fig. 3, through which slots are passed the bolts 7" that fasten the plates to the heads of the chest in a manner to permit of vertical adjustment of the plates and the slide valve to compensate' for wearbetween the plates h, H, I-I, and secure the necessary tight joints between the valve and its seat. In these adj ustahle plates J, J', are secured the exhaust pipes K, L, which ex-- tend some distaneeinto the chest ain-d are arranged in line with eachother and with the hollow piston stems M, M, which areattached to and reciprocate with the slide valve. The exhaust pipes are made of` uniforml diameter throughout their length and are" tihus free f roin shoulders* o'ro'ther projections ou tlellr insides'urtaces,whereby'tlie machinistonen ginee maylool through the exhaust pipe La when the stuing box casting N isn detached,l v

and.l observe' whether the liea'd on. one of theh hollow pistons M is properly centered in t'he exhaust pipes or'whether the valve is properly i fitted toits seat. The' exhaust pipe'L may be made' integral with orfattached to its pliate J, and on the outer endet` this pipeL, which i`s` externally screwed the elbow n of thecasting' N, therother end ot' the elbow n being extended beyond one side of the casting N t'o enable an external exhaust pipe (not shown) to be coupled thereto. Th'e'casling N is thus made so its elbow n' eanbe turned o'n thepipe' L to have its outer' erd face iu any radial di"- rection, to enable theexhaufstsfeamtto be led off to any suitable place; and this casting: N is further provided, at its outer endl, with a stuffing box n', through which passes the valve rod @that extends through th'e pipe L, one of the hollow piston stems M, and' into the exhaust chamber D of the valve D, said inner end of the valve rod having its head! attached to a lug o cast in the inner top or bottom side of the valve D. See Fig. l.

The exhaust pipe-K is threaded into the plate J and provided with an' elbow la which can be turned' with the pipe K to face in any proper direction; andfin theseexhaust pipes K, L, work the pistou stems M, M, which are provided with the enlarged headsm, m, the latter being` grooved circumferentially toreceive' the packing rings lm by which the necessai-y tight joints are secured between the those skilled in the reciprocating piston stems and the exhaust pipes.

It is evident that the exhaust steam admit ted to exhaustchamber D is free to pass in opposite directions through the hollow piston stemsand the exhaust pipes, thus providing for the free escape of the steam from both ends of the chest and reducing theimpact or pressure" of: the exhaust steam or reduce the jar and prevent loosening of the bolts and other parts.

The operation and advantages of my improvements will be readily understood by art from the foregoing description taken in connection with the drawlfngs.

Having thus fully desc'ribedmy invention, what I claim as new, and desireV to secure by Letters Patent, is

1. The" combination with' al piston cylinder andi a steamchest, of the fixed exhaust pipes, th'e' chambered slidevaive having the live t steam recess cl in itsl underside, and: the hol'- lbw' piston stems connected to the valve to communicate" with the exhaust steam` chainber therein `and provided with the heads which tit tightly in" the exhaust pipes, substantially as described.

2. The' combination with a piston cylinder,

and a steam chest, of the slotted seatuplates onthe inside of the steam chest', the chambere`d1 slide valve provided with the slotted f wear plates which ride' upon the seat plates,

` the exhaust pipesand` the hollow piston stems attached" t'o the slide valve and working in` the exhfa-ust pipes, substantially as described.

3. The combination withi thepiston cylinder and a steam chest, o'f the* exhaust pipeK attached to one headi of the steam chest, the

` other exhaust pipeL of uniform diameterat'- tached tothe other head of said steam chest,

f the casting N attached to the protruding end of the exhaust pipe L and having the elrbow 2 u and thestung box, aslide valve, the'hollow piston stems attached to the slide valve and working in the exhaust pipes, and the I valve stern, substantially as described.

Intestiftnony whereof I aitlx my signature in presence of two witnesses.

GEORGE COOK. Witnesses:

HENRY E. COOPER, H. I. BERNHARD.

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